JP2018157249A - Mobile relay device, mobile relay method, and mobile relay system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a terminal device in an area where radio waves from a base station or an access point do not reach to communicate with the base station and the access point in radio communication.SOLUTION: A mobile relay device includes: a radio communication unit for receiving from a terminal device a control signal indicating a state in which the terminal device cannot communicate with a communication destination device; a propelling machine for moving to a position where the mobile relay device is capable of radio communication with the terminal device and the communication destination device; and a control unit for executing a process to relay radio communication between the terminal device and the communication destination device at the position where the mobile relay device is capable of radio communication with the terminal device and the communication destination device if the mobile device has received from the terminal device the control signal indicating the state in which the terminal device cannot radio communicate with the communication destination device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mobile relay device, a mobile relay method, and a mobile relay system that relay wireless communication.

  The amount of communication in wireless communication is increasing. Mobile communication systems and WiFi communication systems are shifting to high frequency bands called millimeter waves. For example, in a communication method called a fifth generation mobile communication system of a mobile communication system, a frequency of 10 GHz or more is used. For example, in the IEEE802.11ad / ay communication system of the WiFi communication system, a frequency of 60 GHz or more is used.

Japanese Patent Laid-Open No. 05-122119 JP 2003-179538 A International Publication No. 2010/150417

  However, as the frequency used for wireless communication increases, the straightness of radio waves increases, and the area where radio waves from base stations and access points called null spots do not reach the terminal increases. For example, the null spot is highly likely to occur in a place that becomes a shadow of an obstacle such as a building, a car, or a person. Since the millimeter wave has a propagation characteristic close to that of light, in a wireless communication system using a high frequency like the millimeter wave, there is a high possibility that the spot becomes a null spot except where the base station and the access point can be seen.

  The present invention relates to a mobile relay device, a mobile relay method, and a mobile relay device that enable communication with a base station or an access point of a terminal device existing in an area where radio waves from a base station or an access point do not reach in wireless communication An object is to provide a relay system.

  One aspect of the present invention is a mobile relay device that includes a wireless communication unit, a propulsion unit, and a control unit. The wireless communication unit receives a control signal indicating that wireless communication with the communication destination device is not possible from the terminal device. The propulsion device moves the mobile relay device to a position where wireless communication with the terminal device and the communication destination device is possible. When the control unit receives a control signal indicating that wireless communication with the communication destination device is not possible from the terminal device, the control unit performs communication between the terminal device and the communication destination device at a position where wireless communication with the terminal device and the communication destination device is possible. Processing related to wireless communication relay is performed.

  According to the disclosed mobile relay device, mobile relay method, and mobile relay system, a terminal device that exists in an area where radio waves from a base station or access point do not reach in wireless communication communicates with the base station or access point. be able to.

FIG. 1 is a diagram illustrating an example of a system configuration of a wireless communication system according to the first embodiment. FIG. 2 is a diagram illustrating an example of a hardware configuration of the mobile relay device. FIG. 3 is a diagram illustrating an example of a functional configuration of the mobile relay device. FIG. 4 is an example of a flowchart of the mobility control process of the control unit of the mobile relay device according to the first embodiment. FIG. 5 is an example of a flowchart of relay control processing of the control unit of the mobile relay device according to the first embodiment. FIG. 6 is a diagram illustrating an example of a sequence up to the start of relay processing of the mobile relay device according to the first embodiment. FIG. 7 is an example of a timing chart of packet transmission, relay, and reception processing of the base station, mobile relay device, and terminal. FIG. 8 is a diagram illustrating an example of setting the directivity of the high frequency antenna in the mobile relay system according to the first embodiment. FIG. 9 is a diagram illustrating an example of a system configuration of a wireless communication system according to the second embodiment. FIG. 10 is a diagram illustrating an example of the mobility control process of the control unit of the mobile relay device according to the second embodiment. FIG. 11A is a diagram illustrating an area configuration of a specific example according to the second embodiment. FIG. 11B is a diagram illustrating an example of a processing sequence in the wireless communication system as a specific example according to the second embodiment. FIG. 12 is an example of a system configuration of a wireless communication system according to the third embodiment. FIG. 13 is a diagram illustrating an example of a hardware configuration of the controller. FIG. 14 is a diagram illustrating an example of a functional configuration of the controller.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configuration of the following embodiment is an exemplification, and the present invention is not limited to the configuration of the embodiment.

<First Embodiment>
FIG. 1 is a diagram illustrating an example of a system configuration of a wireless communication system 100 according to the first embodiment. The wireless communication system 100 is a system in which a mobile relay device provides a mobile relay service for relaying communication with a base station to terminals in a null spot. The radio communication system 100 includes a mobile relay device 1, a base station 2, and a terminal 3. However, FIG. 1 also shows an obstacle for radio wave propagation. The radio communication system 100 is a radio communication system using millimeter waves such as a fifth generation mobile communication system, IEEE802.11ad / ay. However, the communication used in the wireless communication system 100 is not limited to the fifth generation mobile communication, IEEE 802.11ad / ay.

  The mobile relay device 1 is a mobile body such as a drone or an automobile that autonomously flies, for example. In the first embodiment, it is assumed that the mobile relay device 1 is a drone that autonomously flies. The base station 2 is, for example, a carrier network base station, a WiFi access point, or the like. The terminal 3 is a terminal of a user who subscribes to a mobile relay service provided by the wireless communication system 100. The terminal 3 is, for example, a mobile terminal such as a smartphone, a tablet terminal, or a mobile phone terminal. The mobile relay device 1 is an example of a “mobile relay device”. The base station 2 is an example of a “communication destination device”. The terminal 3 is an example of a “terminal device”.

The mobile relay device 1, the base station 2, and the terminal 3 respectively use a low frequency band for control plane communication and a high frequency band for user plane communication. In the first embodiment, the low frequency band is, for example, a 2 GHz band in the case of a mobile communication system, or a 2 GHz band or a 5 GHz band in the case of a WiFi communication system. In the first embodiment, the high frequency band is, for example, a band of 10 GHz or more in the case of a mobile communication system, and a band of 60 GHz or more in the case of a WiFi communication system.

  The control signal is a signal having higher importance than the user signal, and is required to be delivered to the counterpart device more reliably. The radio wave in the low frequency band is less straight ahead than the radio wave in the high frequency band, and reaches the terminal 3 by diffraction or reflection of the radio wave even if an obstacle exists between the base station 2 and the terminal 3. Probability is high. Therefore, in the radio communication system 100 according to the first embodiment, a low frequency band is used in the control plane.

  In the first embodiment, the mobile relay device 1 uses one terminal 3 as a relay target terminal. The mobile relay device 1 is located immediately above the terminal 3 as a position where it can communicate with the terminal 3 and moves following the movement of the terminal 3. In the first embodiment, the mobile relay device 1 flies at a predetermined altitude. The altitude at which the mobile relay device 1 flies is, for example, 10 to 40 m from the ground. For example, the mobile relay device 1 may fly at the altitude of the antenna of the base station 2.

  Therefore, in the first embodiment, the mobile relay device 1 flies at an altitude such that there is no obstacle to the propagation of radio waves in the high frequency band between the mobile relay device 1 and the base station 2, and the base station 2 is communicable. The position of the predetermined altitude at the same latitude and longitude as the terminal 3 in the first embodiment is an example of “a position where wireless communication with the terminal device and the communication destination device” is possible.

  Each of the mobile relay device 1, the base station 2, and the terminal 3 acquires its own location information at a predetermined cycle, and transmits it by broadcast in a low frequency band (control plane). The mobile relay device 1 receives the position information of the terminal 3 and follows the movement of the terminal 3 based on the position information of the terminal 3.

  The terminal 3 is connected to the base station 2 in a high frequency band (user plane) when performing communication involving data transmission / reception. The terminal 3 recognizes the presence of the base station 2 by receiving a beacon signal transmitted from the base station 2 in a high frequency band at a predetermined cycle. When there are obstacles such as buildings, cars, walls, trees, people, etc. between the base station 2 and the terminal 3, radio waves transmitted from the base station 2 in the high frequency band are blocked by the obstacles. The terminal 3 cannot be reached.

When the intensity of radio waves in the high frequency band from the base station 2 is reduced to a level where communication cannot be performed, the terminal 3 transmits a search signal to search for the base station 2. That is, the search signal is transmitted when the terminal 3 enters the null spot. The search signal is one of the control signals and is transmitted by broadcast. In the first embodiment, since the search signal is used to search for the base station 2 in the high frequency band, the search signal transmitted from the terminal 3 is transmitted in the high frequency band. The search signal is, for example, an LTE (Long Term Evolution) synchronization signal or a WiFi probe request signal. The search signal is an example of a “control signal indicating that wireless communication with the communication destination device is not possible”.

  The mobile relay device 1 is located immediately above the terminal 3 and receives a search signal from the terminal 3. The mobile relay device 1 starts relaying high-frequency band wireless communication between the terminal 3 and the base station 2 when receiving the search signal from the terminal 3. Thereby, in the first embodiment, even when the terminal 3 exists in a place where wireless communication with the base station 2 in the high frequency band is not possible, the terminal 3 can perform communication in the high frequency band.

In the first embodiment, since the mobile relay device 1 moves following the movement of the terminal 3, it moves between cells of a plurality of base stations 2. The mobile relay device 1 performs a handover when moving between cells. The handover of the mobile relay device 1 conforms to standards such as the fifth generation mobile communication system, IEEE802.11ad / ay. Therefore, in 1st Embodiment, it does not mention in particular about the hand-over between the base stations 2 of the mobile relay apparatus 1. FIG.

<Device configuration>
FIG. 2 is a diagram illustrating an example of a hardware configuration of the mobile relay device 1. In the example shown in FIG. 2, it is assumed that the mobile relay device 1 is a drone. The mobile relay device 1 includes, as hardware components, a processor 101, a RAM (Random Access Memory) 102, a nonvolatile memory 103, a prime mover 104A, a propulsion device 104B, a positioning unit 105, a low-frequency wireless communication unit 106, a low-frequency Antenna 107, high-frequency radio communication unit 108, and high-frequency antenna 109.

  The RAM 102 is a volatile memory. The RAM 102 provides a work area for the processor 101. The nonvolatile memory 103 is, for example, a flash memory. The nonvolatile memory 103 stores an OS (Operating System), a mobile relay program, and various other programs. The mobile relay program is a program for relaying wireless communication between the base station 2 and the terminal 3.

The processor 101 executes various processes by loading the OS and various application programs held in the nonvolatile memory 103 into the RAM 102 and executing them. The processor 101 is, for example, a CPU (Central Processing Unit). The number of processors 101 is not limited to one, and a plurality of processors 101 may be provided. The processor 101 is an example of a “control unit”.

  The prime mover 104A is, for example, an engine or a motor. The prime mover 104A converts, for example, electric power into the power of the propulsion device 104B. The propulsion device 104B is, for example, a propeller. The propulsion machine B propels the mobile relay device 1 using the power input from the prime mover 104A. When the mobile relay device 1 is an automobile, for example, the prime mover 104A is a gasoline engine and the propulsion device 104B is a wheel. The prime mover 104A and the propulsion device 104B are controlled by the processor 101. The prime mover 104A is driven and stopped by an instruction from the processor 101. The propulsion device 104B moves in the direction and distance indicated by the processor 101. The propulsion device 104B is an example of a “propulsion device”.

  The position positioning unit 105 receives a signal that is an information source of the current position of the mobile relay device 1. A signal that is an information source of the current position of the apparatus is hereinafter referred to as a position signal. The positioning unit 105 is, for example, a GPS signal receiver or a BLE beacon receiver. From the position signal received by the position measurement unit 105, for example, the latitude and longitude of the current position of the mobile relay device 1 are acquired. The position signal acquired by the position positioning unit 105 is output to the processor 101.

  The low frequency antenna 107 receives and transmits a low frequency band radio signal. The low frequency radio communication unit 106 converts the radio signal received by the low frequency antenna 107 into an electric signal, further converts it into a baseband signal, and outputs it to the processor 101. The low-frequency radio communication unit 106 converts the baseband signal input from the processor 101 into an electric signal, further converts it into a radio signal, and transmits the radio signal from the low-frequency antenna 107. The low-frequency wireless communication unit 106 is an example of a “second wireless communication unit”.

The high-frequency radio communication unit 108 and the high-frequency antenna 109 perform the same processing as the low-frequency radio communication unit 106 and the low-frequency antenna 107 on the radio signal in the high frequency band, respectively. The high frequency antenna 109 is an antenna with variable directivity. The high frequency antenna 109 is, for example, one, and the directivity is adjusted for each of the base station 2 and the terminal 3 by adjusting the phase. Alternatively, the high-frequency antenna 109 includes, for example, two for the base station 2 and one for the terminal 3, and the directivity is adjusted by matching the direction of each antenna to the base station 2 or the terminal 3. May be.

  The directivity is the relationship between the radiation direction of radio waves and the radiation intensity. Matching the directivity of the antenna means adjusting the radiation direction or the incident direction of the antenna radio wave so that the intensity of the radio wave transmitted to the object or the radio wave received from the object becomes stronger. The low-frequency antenna 107 may be an omnidirectional antenna. The high frequency wireless communication unit 108 is an example of a “wireless communication unit”. The high frequency antenna 109 is an example of an “antenna”.

  Note that the hardware configuration of the mobile relay device 1 shown in FIG. 2 is an example, and is not limited to the above, and components can be omitted, replaced, or added as appropriate according to the embodiment. For example, the mobile relay device 1 may further include an acceleration sensor, a geomagnetic sensor, or the like as the position positioning unit 105. For example, the mobile relay device 1 may include a portable recording medium driving device and execute a program recorded on the portable recording medium. The portable recording medium is a recording medium such as a miniSD card or a microSD card.

  FIG. 3 is a diagram illustrating an example of a functional configuration of the mobile relay device 1. The mobile relay device 1 includes, as functional components, a control unit 11, a position information receiving unit 12, a position estimating unit 13, a directivity control unit 14, a low frequency receiving unit 15A, a low frequency transmitting unit 15B, a peripheral device information database (DB). ) 16, a high frequency receiving unit 17A, a high frequency transmitting unit 17B, and a relay processing unit 18. These functional components are functional components achieved by the processor 101 of the mobile relay device 1 executing the mobile relay program in the nonvolatile memory 103.

  The position information receiving unit 12 is an interface with the position positioning unit 105. The position information receiving unit 12 receives a position signal input from the position positioning unit 105. The position information receiving unit 12 outputs a position signal to the position estimating unit 13.

  The position estimation unit 13 estimates the current position of the mobile relay device 1 based on the position signal input from the position information reception unit 12 and acquires the estimated current position as the position information of the mobile relay device 1. The position information of the mobile relay device 1 includes, for example, latitude, longitude, and altitude. The position estimation unit 13 outputs the acquired position information to the control unit 11.

  The directivity control unit 14 controls the directivity of the high frequency antenna 109 in accordance with an instruction from the control unit 11. The directivity control unit 14 receives the position information of the mobile relay device 1, the base station 2, and the terminal 3 from the control unit 11, and based on the position information of the mobile relay device 1, the base station 2, and the terminal 3, The directivity of the frequency antenna 109 is controlled.

  When there is one high-frequency antenna 109, the directivity control unit 14 controls the phase of the high-frequency antenna 109 so that the radiation direction matches the base station 2 and the terminal 3. When two high-frequency antennas 109 are provided for the base station 2 and for the terminal 3, the directivity control unit 14 sets the high frequency antennas so that the radiation directions of the base station 2 and the terminal 3 are matched. The direction of the frequency antenna 109 is controlled. The directivity control method is not limited to a predetermined method, and any existing method may be used.

  The low frequency receiving unit 15A and the low frequency transmitting unit 15B are interfaces with the low frequency wireless communication unit 106. The low frequency receiving unit 15 </ b> A receives an input from the low frequency wireless communication unit 106 and outputs it to the control unit 11. The low frequency transmission unit 15B receives an input from the control unit 11 and outputs the input to the low frequency wireless communication unit 106.

The signal input from the low frequency radio communication unit 106 to the low frequency receiving unit 15A is, for example,
It is a control signal transmitted from the base station 2 and the terminal 3 in the low frequency band. One of control signals transmitted from the base station 2 and the terminal 3 in the low frequency band is the position information of the base station 2 and the terminal 3. Each of the base station 2 and the terminal 3 acquires position information at a predetermined cycle, and transmits the acquired position information in a low frequency band by broadcasting. The position information includes, for example, terminal identification information, latitude and longitude of the base station 2 and the terminal 3. One of the signals input from the control unit 11 to the low frequency transmission unit 15B is a control signal including the position information of the mobile relay device 1 transmitted by the mobile relay device 1.

  The high frequency receiving unit 17A and the high frequency transmitting unit 17B are interfaces with the high frequency wireless communication unit 108. The high frequency receiving unit 17 </ b> A receives an input from the high frequency wireless communication unit 108 and outputs the input to the relay processing unit 18. The high frequency transmission unit 17B receives the input from the relay processing unit 18 and outputs it to the high frequency radio communication unit 108. The search signal from the terminal 3 is input to the high frequency receiving unit 17A. Since the search signal is transmitted by broadcast, the search signal is input to the relay processing unit 18 from the high frequency receiving unit 17 </ b> A and output from the relay processing unit 18 to the control unit 11.

  The relay processing unit 18 performs relay processing for communication between the base station 2 and the terminal 3. The relay processing unit 18 performs predetermined processing on the data input from the high frequency receiving unit 17A and outputs the data to the high frequency transmitting unit 17B. The relay method performed by the relay processing unit 18 may be any existing wireless signal relay method, and is not limited to a predetermined relay method. For example, the relay processing unit 18 performs processing such as shaping and amplification of the signal input from the high frequency receiving unit 17A, and outputs the processed signal to the high frequency transmitting unit 17B.

  The relay processing unit 18 is input with data addressed to the mobile relay device 1 itself from the high frequency receiving unit 17A and data with the mobile relay device 1 itself as the transmission source from the control unit 11. The relay processing unit 18 outputs data addressed to the mobile relay device 1 itself to the control unit 11. Since the search signal transmitted by broadcast is one of the data destined for the mobile relay device 1, the relay processing unit 18 outputs the search signal input from the high frequency receiving unit 18A to the control unit 11.

  The relay processing unit 18 outputs data from which the mobile relay device 1 itself is a transmission source to the high frequency transmission unit 17B. For example, data transmitted from the control unit 11 to the relay processing unit 18 that is the transmission source of the mobile relay device 1 itself is transmitted to the base station 2 for the mobile relay device 1 to start communication relay in a high frequency band. There are control signals used in the connection sequence.

  The control unit 11 sets a position signal acquisition cycle for the position measurement unit 105. The period for acquiring the position signal is, for example, 10 seconds. However, the position signal acquisition cycle is not limited to 10 seconds. The position information of the mobile relay device 1 is input from the position estimation unit 13 to the control unit 11 at a position signal acquisition cycle.

  When the position information is input from the position estimation unit 13, the control unit 11 generates a control signal including the position information of the mobile relay device 1, and outputs the generated control signal to the low frequency transmission unit 15B. The control signal including the position information of the mobile relay device 1 is transmitted by broadcast. Therefore, the transmission cycle of the control signal including the position information of the mobile relay device 1 is the same as the acquisition cycle of the position signal. The control signal including the position information of the mobile relay device 1 may include information such as the moving speed, transmission power, and minimum reception sensitivity of the mobile relay device 1.

  The control unit 11 receives a control signal including position information of the base station 2 and the terminal 3 from the low frequency receiving unit 15A. The control unit 11 stores the position information of the base station 2 and the terminal 3 included in the control signal from the low frequency receiving unit 15A in the peripheral device information DB 16.

  When the control signal including the position information of the terminal 3 to be relayed is input from the low frequency receiving unit 15A, the control unit 11 compares the position information of the terminal 3 and the position information of the mobile relay device 1, for example. As a result of the comparison between the position information of the terminal 3 and the position information of the mobile relay device 1, if the latitude and longitude do not match, the control unit 11 returns the latitude and longitude indicated by the latest position information of the terminal 3. The movement is determined, the latest position information of the terminal 3 is notified to the propulsion device 104B as the movement destination, and the movement is instructed. As a result of the comparison between the position information of the terminal 3 and the position information of the mobile relay device 1, if the latitude and longitude match, the control unit 11 does not determine the movement of the mobile relay device 1 and the mobile relay device 1. Will stop at the current location.

  In addition, when the control signal including the position information of the relay target terminal 3 is input from the low frequency reception unit 15A, the control unit 11 determines, for example, whether or not the position information of the terminal 3 is changed. May be. When there is a change in the position information of the terminal 3, the control unit 11 determines the movement to the latitude and longitude indicated by the latest position information of the terminal 3, and the propulsion device 104B has the latest terminal 3 as the movement destination. Notify location information and instruct to move. When there is no change in the position information of the terminal 3, the control unit 11 does not determine the movement of the mobile relay device 1.

  The control unit 11 receives an input of a search signal from the relay target terminal 3 from the relay processing unit 18. When the control unit 11 detects a search signal from the terminal 3 to be relayed, the control unit 11 transmits a connection request to the base station 2. The connection request is, for example, one of signals transmitted to the base station 2 in an LTE connection sequence with the base station 2. The connection request is, for example, a WiFi association procedure. The connection request is output from the control unit 11 to the high frequency transmission unit 17B through the relay processing unit 18 and transmitted in the high frequency band.

  The control unit 11 receives an input of a response from the base station 2 to the connection request from the high frequency receiving unit 17A. The response to the connection request from the terminal 3 is, for example, one of signals transmitted from the base station 2 in the LTE connection sequence with the base station 2. The response to the connection request is, for example, WiFi CTS (Clear To Send).

  When receiving a response from the base station 2 in response to the connection request, the control unit 11 reads the position information of the base station 2 and the terminal 3 from the peripheral device information DB 16 and directivity together with the position information of the base station 2 and the terminal 3. The control unit 14 is instructed to control the directivity of the high frequency antenna 109. Further, when the directivity control unit 14 completes the directivity control of the high-frequency antenna 109, the control unit 11 instructs the relay processing unit 18 to start relaying.

  The peripheral device information DB 16 stores location information of the base station 2 and the terminal 3 and terminal identification information of the terminal 3 with which the service of the wireless communication system 100 is contracted. When the mobile relay program is installed, a storage area in the nonvolatile memory 103 is reserved for the peripheral device information DB 16. The control signal including the position information from the base station 2 and the terminal 3 includes the identification information of the base station 2 and the terminal 3, and the peripheral device information DB 16 includes the position information of the base station 2 and the terminal 3. Stored with identification information.

<Process flow>
FIG. 4 is an example of a flowchart of the mobility control process of the control unit 11 of the mobile relay device 1 according to the first embodiment. The movement control process is a process for controlling the movement of the mobile relay device 1. The process shown in FIG. 4 is started when a control signal including the position information of the terminal 3 is received. Since the terminal 3 transmits the position information of the terminal 3 at a predetermined cycle, the process shown in FIG. 4 is executed at a cycle at which the terminal 3 transmits the position information. The execution subject of the processing shown in FIG. 4 is the processor 101 of the mobile relay device 1, but for convenience, the description will be made with the control unit 11 that is a functional component as the subject. Hereinafter, the position information of the terminal 3 is referred to as terminal position information.

  In OP1, the control unit 11 acquires terminal location information from the control signal input from the low-frequency receiving unit 15A. In OP2, the control unit 11 determines whether the terminal position information input from the low frequency receiving unit 15A is that of the relay target terminal 3. For example, when the terminal identification information included in the control signal together with the terminal position information matches the terminal identification information of the terminal 3 with which the service of the wireless communication system 100 stored in the peripheral device information DB 16 is contracted. It is determined that the position information is the target terminal 3.

  If the terminal location information input from the low frequency receiving unit 15A is that of the terminal 3 to be relayed (OP2: YES), the process proceeds to OP3. In OP3, the control unit 11 stores the terminal position information in the peripheral device information DB 16. When the terminal position information input from the low frequency receiving unit 15A is not for the terminal 3 to be relayed (OP2: NO), the processing illustrated in FIG. 4 ends.

  In OP4, the control unit 11 determines whether the latitude and longitude included in the terminal position information match the latitude and longitude of the current position of the mobile relay device 1. In this determination, if the latitude and longitude of the current position of the mobile relay device 1 are within a predetermined allowable range from the latitude and longitude included in the terminal position information, it is determined that they match. When the latitude and longitude included in the terminal position information match the latitude and longitude of the current position of the mobile relay device 1 (OP4: YES), the movement of the mobile relay device 1 is not determined and is shown in FIG. Processing ends. If the latitude and longitude included in the terminal position information do not match the latitude and longitude of the current position of the mobile relay device 1 (OP4: NO), the process proceeds to OP5.

  In OP5, the control unit 11 determines the movement to the position of the latitude and longitude included in the terminal position information, notifies the propulsion device 104B of the latitude and longitude included in the terminal position information as the movement destination, and instructs the movement. . The altitude of the mobile relay device 1 is not changed. As a result, the mobile relay device 1 follows the movement of the terminal 3 and moves right above the terminal 3. The process of OP5 is an example of “determining a position where wireless communication is possible with the terminal device and the communication destination device based on the position information of the terminal device”.

  FIG. 5 is an example of a flowchart of the relay control process of the control unit 11 of the mobile relay device 1 according to the first embodiment. The relay control process is a process for controlling relay of communication between the base station 2 and the terminal 3. The process shown in FIG. 5 is started when a search signal is received from the terminal 3 to be relayed. The execution subject of the processing shown in FIG. 5 is the processor 101 of the mobile relay device 1, but for convenience, the description will be made with the control unit 11 that is a functional component as the subject.

  In OP11, the control unit 11 receives a search signal input from the relay target terminal 3 from the high frequency receiving unit 17A. In OP12, the control unit 11 transmits a connection request to the base station 2 in the high frequency band through the high frequency transmission unit 17B. As the connection request destination base station 2, for example, the base station 2 having the highest intensity of radio waves received by the mobile relay device 1 is selected.

  In OP13, the control unit 11 determines whether a response from the base station 2 to the connection request has been received. When a response from the base station 2 to the connection request is input from the high frequency receiver 17A (OP13: YES), the process proceeds to OP14. Until the response from the base station 2 to the connection request is input from the high frequency receiving unit 17A (OP13: NO), the process of OP13 is repeatedly executed.

  In OP14, the control unit 11 instructs the directivity control unit 14 to control the directivity of the high frequency antenna 109. The control unit 11 reads the latest position information of the base station 2 and the terminal 3 from the peripheral device information DB 16 and notifies the directivity control unit 14 of the information.

  In OP15, the control unit 11 activates the relay processing unit 18. Thereby, relay of communication between the base station 2 and the terminal 3 is started. Thereafter, the process shown in FIG. 5 ends. Thereafter, when the communication between the base station 2 and the terminal 3 is completed, the relay processing unit 18 stops its operation. The process illustrated in FIG. 5 is an example of “a process related to relay of wireless communication between the terminal apparatus and the communication destination apparatus”.

  FIG. 6 is a diagram illustrating an example of a sequence until the relay start of communication between the base station 2 and the terminal 3 in the mobile relay device 1 according to the first embodiment. In the example illustrated in FIG. 6, for example, it is assumed that the user carrying the terminal 3 is moving.

  In S1 and S2, the base station 2 and the terminal 3 respectively transmit position information at a predetermined cycle. When receiving the location information of the base station 2 and the terminal 3, the mobile relay device 1 stores it in the peripheral device information DB 16 (FIG. 4, OP2).

  In S3, since the user of the terminal 3 is moving, the position information of the terminal 3 is changed, and the mobile relay device 1 has the same latitude and longitude of the current position of the mobile relay device 1 and the position of the terminal 3. Is determined (FIG. 4, OP3: NO). In S4, the mobile relay device 1 moves directly above the terminal 3 (FIG. 4, OP4).

  In S5, for example, when the user of the terminal 3 enters the shadow of a building, the intensity of the radio wave from the base station 2 received by the terminal 3 decreases, and the terminal 3 becomes unable to communicate with the base station 2. . In S6, the terminal 3 broadcasts a search signal in a high frequency band.

  In S7, the mobile relay device 1 receives the search signal transmitted from the terminal 3 (FIG. 5, OP11), and transmits a connection request to the base station 2 in the high frequency band (FIG. 5, OP12). In S8, the base station 2 transmits a response to the connection request in the high frequency band. The mobile relay device 1 receives a response to the connection request from the base station 2 (FIG. 5, OP13: YES), and starts relay processing (FIG. 5, OP15). Thereby, thereafter, a connection sequence is performed between the base station 2 and the terminal 3, and communication is started.

  FIG. 7 is an example of a timing chart of packet transmission, relay, and reception processes of the base station 2, the mobile relay device 1, and the terminal 3, respectively. In the first embodiment, the mobile relay device 1 sets the phase of the high frequency antenna 109 for the base station 2 and the terminal 3 respectively, or sets separate antennas for the base station 2 and the terminal 3. Hold. As a result, the mobile relay device 1 can perform packet transmission to the terminal 3 in parallel with reception of the packet from the terminal 32. Therefore, in the relay processing for communication between the base station 2 and the terminal 3 by the mobile relay device 1, the delay can be suppressed small.

  FIG. 8 is a diagram illustrating an example of setting the directivity of the high-frequency antenna 109 in the wireless communication system 100 according to the first embodiment. In the first embodiment, the high frequency antenna 109 of the mobile relay device 1 is a directional antenna. When the mobile relay device 1 relays communication between the base station 2 and the terminal 3, the mobile relay device 1 adjusts the directivity of the high frequency antenna 109 according to the respective positions of the base station 2 and the terminal 3.

  By adjusting the directivity of the high frequency antenna 109, the direction in which the radio wave transmitted from the high frequency antenna 109 is diffused can be limited. As a result, the radio wave of communication between the base station 2 and the mobile relay device 1 and the radio wave of communication between the mobile relay device 1 and the terminal 3 and the area where the radio wave of other communication from the base station 2 is interfered (interference area). Can reduce the area that interferes with radio waves of other communications from the terminal 3 (interference area).

<Operational effects of the first embodiment>
In the first embodiment, the mobile relay device 1 moves to a position where wireless communication is possible between the terminal 3 and the base station 2 and receives a search signal from the terminal 3, the wireless communication between the terminal 3 and the base station 2. Relay. As a result, even when the terminal 3 cannot communicate with the base station 2 wirelessly, the terminal 3 can communicate with the base station 2.

  In the first embodiment, the mobile relay device 1 acquires the position information of the terminal 3, determines a position where wireless communication is possible between the terminal 3 and the base station 2 based on the position information of the terminal 3, and the determined position Move to. Thereby, even when the terminal 3 enters the null spot, the mobile relay device 1 moves to a position where wireless communication is possible between the terminal 3 and the terminal 2 and relays communication between the terminal 3 and the base station 2. Even if 3 enters the null spot, communication with the base station 2 can be performed.

  In the first embodiment, the mobile relay device 1 follows the movement of the terminal 3 and moves right above the terminal 3 and receives a search signal transmitted when the terminal 3 enters the null spot. Relay of communication between the base station 2 and the terminal 3 is started. Thereby, communication with the base station 2 of the terminal 3 in the null spot in communication using a high frequency band can be enabled.

  The mobile relay device 1 flies at a predetermined altitude from the ground, avoids obstacles of radio waves in the high frequency band with the base station 2, and maintains a state in which communication with the base station 2 in the high frequency band is possible. Further, since the mobile relay device 1 flies directly above the terminal 3, it can maintain a state in which it can communicate with the terminal 3 in a high frequency band.

  Further, according to the first embodiment, it is possible to take measures against a null spot without newly installing a base station. As a result, costs such as base station installation costs, place costs, and line costs can be reduced.

  In the first embodiment, the mobile relay device 1 moves right above the terminal 3, but the destination of the mobile relay device 1 is not limited to this. For example, the mobile relay device 1 may use the latitude and longitude of an intermediate point between the terminal 3 and the base station 2 as the destination. The mobile relay device 1 only needs to move to a position between the terminal 3 and the base station 2 so that both the terminal 3 and the base station 2 can communicate with each other in the high frequency band.

Second Embodiment
FIG. 9 is a diagram illustrating an example of a system configuration of the wireless communication system 100 according to the second embodiment. A wireless communication system 100 according to the second embodiment includes a mobile relay device 1, a base station 2, and a plurality of terminals 3. In the second embodiment, the mobile relay device 1 is set with a responsible area, and relays communication between the terminal 3 and the base station 2 in the responsible area.

  The size of one area is, for example, 10 to 20 m in diameter. The area in charge of the mobile relay device 1 is assumed to be an adjacent area. The mobile relay device 1 relays the communication only to a user terminal that subscribes to a service provided by the wireless communication system 100. In the second embodiment, the base station 2 to which the mobile relay device 1 is connected is fixed to one unit.

  For example, in the example shown in FIG. 9, the areas in charge of the mobile relay device 1 are area A, area B, and area C. In the second embodiment, the mobile relay device 1 flies at a predetermined altitude and moves over an area having the largest number of terminals 3 that cannot communicate with the base station 2. Relay of communication. In addition, the mobile relay device 1 adjusts the directivity of the high frequency antenna 109 so that the entire coverage area can be covered even at the destination. The altitude at which the mobile relay device 1 flies is, for example, 10 to 40 m from the ground. For example, the mobile relay device 1 may fly at the altitude of the antenna of the base station 2.

  In the second embodiment, descriptions overlapping with those in the first embodiment are omitted. In the second embodiment, the hardware configuration of the mobile relay device 1 is the same as that of the first embodiment. The functional configuration of the mobile relay device 1 according to the second embodiment is a configuration in which an area information database including information on the area in charge of the mobile relay device 1 is added to the functional configuration of the first embodiment. However, in 2nd Embodiment, the process of the control part 11 of the mobile relay apparatus 1 differs from 1st Embodiment.

  The area information DB is created in the storage area in the non-volatile memory 103 when the mobile relay program is installed. In the area information DB, identification information and an area range are stored for each area in charge of the mobile relay device 1. The area range is defined by, for example, latitude and longitude.

  FIG. 10 is a diagram illustrating an example of the mobility control process of the control unit 11 of the mobile relay device 1 according to the second embodiment. The example shown in FIG. 10 is executed at a predetermined cycle, for example. The execution cycle of the process shown in FIG. 10 is set, for example, on the order of 10 seconds. The execution subject of the processing shown in FIG. 10 is the processor 101 of the mobile relay device 1, but for convenience, the description will be made with the control unit 11 that is a functional component as the subject.

  In OP21, the control unit 11 determines whether or not a search signal is input from the high frequency receiving unit 17A. When the input of the search signal is received (OP21: YES), the process proceeds to OP22. If no search signal is received after a predetermined time has elapsed (OP21: NO), the processing shown in FIG. 10 ends. The predetermined time is, for example, 1 second.

  In OP22, the control unit 11 determines whether or not the terminal 3 that is the source of the search signal is the terminal 3 in the assigned area. For example, the control unit 11 searches the peripheral device information DB 16 with the identification information of the terminal 3 that is the source of the search signal. When the position information of the terminal 3 that is the source of the search signal is stored in the peripheral device information DB 16 and the position information of the terminal 3 indicates the area in charge, the control unit 11 determines that the terminal 3 is in the area in charge. It is determined that it exists inside. For example, if the location information of the terminal 3 that is the source of the search signal is stored in the peripheral device information DB 16, but the location information of the terminal 3 indicates outside the assigned area, the control unit 11 Is determined not to exist in the area in charge. For example, the control unit 11 discards the search signal when the terminal 3 that is the source of the search signal is not the terminal 3 that contracts for the service provided by the wireless communication system 100.

  If the terminal 3 that is the source of the search signal is the terminal 3 in the assigned area (OP22: YES), the process proceeds to OP23. When the terminal 3 that is the source of the search signal is not the terminal 3 in the assigned area (OP22: NO), the processing shown in FIG.

  In OP23, the control unit 11 transmits a terminal detection signal in a high frequency band at a predetermined position for each assigned area, and detects the number of terminals 3 to which a response signal is returned. This confirms that the terminal 3 in the assigned area can communicate with the mobile relay device 1 in the high frequency band. Specific processing is as follows. However, the detected terminal 3 is the terminal 3 that has contracted for the service provided by the wireless communication system 100.

For example, in each assigned area, a transmission point of the terminal detection signal is determined. The mobile relay device 1 instructs the propulsion device 104B to move the terminal detection signal in the area where it is currently located to the transmission point. When the movement of the terminal detection signal to the transmission point is completed, the control unit 11 transmits the terminal detection signal through the relay processing unit 18 and the high frequency transmission unit 17B. The control unit 11 counts the number of terminals 3 in the assigned area that receives the response signal from the terminal 3 through the high frequency receiving unit 17A and the relay processing unit 18. Whether or not the terminal 3 from which the response signal has been received is present in the assigned area where the mobile relay device 1 is located is determined based on the position information of the terminal 3 stored in the peripheral device information DB 16. When the counting of the number of terminals 3 from which the response signal is received is completed, the control unit 11 instructs the propulsion device 104B to move the terminal signal in the adjacent assigned area to the transmission point.

  For example, LTE UE Capability Enquiry and UE Capability Response are used for the terminal detection signal and the response signal, respectively. In addition, for example, a WiFi beacon signal and a probe signal are used for the terminal detection signal and the response signal, respectively. The process of OP23 is an example of “detecting the number of terminal devices capable of wireless communication with the own device in each of a plurality of areas”.

  In OP24, the control unit 11 determines the area having the largest number of terminals for which the response signal to the terminal detection signal has been received as the movement destination, and sends an instruction to move to the movement destination area to the propulsion device 104B. For example, the transmission point of the terminal detection signal in the area in charge of the movement destination is designated as the movement destination. The transmission point of the terminal detection signal in each assigned area is an example of “a predetermined position in the area”. The process of OP24 is an example of “determining a predetermined position in an area satisfying a predetermined condition among the plurality of areas as a position where wireless communication with the terminal device and the communication destination device is possible”. The area having the largest number of terminals that have received a response signal to the terminal detection signal is an example of “an area that satisfies a predetermined condition among the plurality of areas”.

  In OP25, the control unit 11 determines whether or not the movement to the designated movement destination is completed. When the movement to the designated movement destination is completed (OP25: YES), the process proceeds to OP26. If the movement to the designated movement destination is not completed (OP25: NO), the process of OP25 is repeatedly executed.

  In OP26, the control unit 11 instructs the directivity control unit 14 to control the directivity of the high frequency antenna 109. The control unit 11 notifies the directivity control unit 14 of the current position and information on the range of each assigned area in the area information DB. The directivity control unit 14 controls the directivity of the high frequency antenna 109 so as to cover all the assigned areas at the current position. The process of OP26 is an example of “controlling the directivity of the antenna so that radio waves in the second frequency band can reach the plurality of areas”.

  In OP27, the control unit 11 starts the relay control process shown in FIG. 5 at the current position. Thereafter, the process shown in FIG. 10 ends. In the second embodiment, the relay control process is the same as in the first embodiment (see FIG. 5), and the mobile relay device 1 transmits a connection request to the base station 2 when receiving the search signal. When a response to the connection request is received from the base station 2, relaying of communication between the terminal 3 and the base station 2 is started.

<Specific example>
FIG. 11A is a diagram illustrating an area configuration of a specific example according to the second embodiment. In a specific example, the areas in charge of the mobile relay device 1 are assumed to be area A, area B, and area C. Area A, area B, and area C are areas that are continuously adjacent to each other. Area A, area B, and area C are not null spots due to a fixed obstacle (such as a building).

  The number of terminals 3 in the area is premised on area A> area B> area C. Further, it is assumed that the mobile relay device 1 is stopped above the area A.

For example, when the area A becomes a null spot due to a moving obstacle such as a truck or a bus, the intensity of the radio wave in the high frequency band from the base station 2 received by the terminal 3 in the area A is reduced. Of the terminal 3 cannot communicate with the base station 2 in the high frequency band. In this case, the terminal 3 in the area A transmits a search signal to search for the base station 2. In the specific example, the process of the mobile relay device 1 when a search signal from the terminal 3 in the area A is received will be described.

  FIG. 11B is a diagram illustrating an example of a processing sequence in the wireless communication system 100 as a specific example according to the second embodiment. FIG. 11B is based on the area configuration shown in FIG. 11A. It is assumed that the mobile relay device 1 is located above the area A.

  In S11, a search signal is transmitted from the terminal 3 in the area A. The mobile relay device 1 receives the search signal from the terminal 3 in the area A (OP21 in FIG. 10). In S12, the mobile relay device 1 moves to the transmission point of the terminal detection signal in the area A, transmits the terminal detection signal, and detects the number of terminals 3 from which the response signal in the area A is received (FIG. 10). , OP23).

  In S13, the mobile relay device 1 moves to area B, which is the next area. In S14, the mobile relay device 1 moves to the transmission point of the terminal detection signal in the area B, transmits the terminal detection signal, and detects the number of terminals 3 that receive the response signal in the area B (FIG. 10). , OP23).

  In S15, the mobile relay device 1 moves to area C, which is the next area. In S16, the mobile relay device 1 moves to the transmission point of the terminal detection signal in area C, transmits the terminal detection signal, and detects the number of terminals 3 that receive the response signal in area C (FIG. 10). , OP23).

  In S17, the mobile relay device 1 determines the area A having the largest number of terminals among the areas A, B, and C as the destination (FIG. 10, OP24). In S18, the mobile relay device 1 moves to the area A. In S18, for example, the mobile relay device 1 moves to the transmission point of the terminal detection signal in the area A.

  In S19, the mobile relay device 1 controls the directivity of the high-frequency antenna 109 so that the area B and the area C can be covered while being positioned above the area A (OP26 in FIG. 10). In S20, the mobile relay device 1 receives the search signal from the terminal 3 in the area A (OP11 in FIG. 5). Thereafter, the relay control process shown in FIG. 5 is performed, and the communication between the base station 2 and the terminal 3 is relayed by the mobile relay device 1.

  The mobile relay device 1 stays above the area A and relays communication between the terminal 3 and the base station 2, but receives a search signal from the terminal 3 in the assigned area other than the area A. Also relays communication of the terminal 3. That is, in the second embodiment, the mobile relay device 1 is controlled to move to a place where the access of the terminals 3 is expected to be concentrated.

<Effects of Second Embodiment>
In the second embodiment, when the mobile relay device 1 flies over the assigned area and receives a search signal from the terminal 3 in the area, the mobile relay device 1 moves to the area where the terminal 3 is present most frequently and relays communication. As a result, more terminals 3 existing at the null spot in the area in charge of the mobile relay device 1 can communicate with the base station 2 in the high frequency band.

  In the second embodiment, since the mobile relay device 1 is responsible for a plurality of areas, the number of mobile relay devices 1 used in the wireless communication system 100 can be reduced.

  In the second embodiment, the mobile relay device 1 controls the directivity of the high frequency antenna 109 so as to cover the entire assigned area. As a result, it is possible to prevent the search signal from the terminal 3 in each assigned area from being missed.

  In 2nd Embodiment, the mobile relay apparatus 1 moves to the transmission point of the terminal detection signal of each charge area, transmits a terminal detection signal in a high frequency band, and counts the number of the terminals 3 which a response signal returns. As a result, the number of terminals 3 that can communicate with the mobile relay device 1 in a high frequency band in each assigned area can be detected more accurately.

  In the second embodiment, the mobile relay device 1 moves to an area having the largest number of terminals 3 that respond to the terminal detection signal, and relays communication between the terminals 3 and the base station 2. However, the condition for determining the destination of the mobile relay device 1 is not limited to the largest number of terminals 3 that return a response to the terminal detection signal. For example, the condition for determining the destination of the mobile relay device 1 may be that the number of terminals 3 that return a response to the terminal detection signal is the smallest.

  In the first and second embodiments, the mobile relay device 1 has been described on the assumption that the mobile relay device 1 relays communication between the fixed base station 2 and the terminal 3. However, the present invention is not limited to this, and the mobile relay device 1 may relay communication between another mobile relay device and the terminal 3. When the mobile relay device 1 relays communication between another mobile relay device and the terminal 3, both the mobile relay device 1 and the other mobile relay device fly at a predetermined altitude from the ground. A state where communication is possible can be maintained. Also, other mobile relay apparatuses also transmit their own position information by broadcast at a predetermined cycle. Therefore, the mobile relay device 1 can acquire the position information of the other mobile relay devices, and the communication between the other mobile relay devices and the terminal 3 can be performed by performing the same processing as in the first or second embodiment. Can be relayed. When the mobile relay device 1 relays communication between another mobile relay device and the terminal 3, the other mobile relay device is an example of a “communication destination device”.

<Third Embodiment>
In the first and second embodiments, the mobile relay device 1 itself determines the destination according to the position of the terminal 3 and determines the start of the relay process. In the third embodiment, the mobile relay device 1 does not perform the determination process, and the controller that centrally manages the plurality of mobile relay devices 1 determines the destination of the mobile relay device 1 and determines the start of the relay processing.

  FIG. 12 is an example of a system configuration of a wireless communication system 100C according to the third embodiment. The wireless communication system 100C according to the third embodiment includes a plurality of mobile relay devices 1, a base station 2, a terminal 3, and a controller 4 that centrally manages the plurality of mobile relay devices 1. The controller 4 communicates with the mobile relay device 1 and the base station 2 in a control plane, that is, in a low frequency band. The mobile relay device 1 communicates with the controller 4 via the base station 2. However, in FIG. 12, for convenience, the mobile relay device 1 and the controller 4 are displayed so as to perform direct communication. The controller 4 is an example of a “control device”. A system including the controller 4 and the plurality of mobile relay apparatuses 1 is an example of a “mobile relay system”.

  For example, in the wireless communication system 100C, as in the first embodiment, the mobile relay device 1 moves following the terminal 3 and detects the search signal from the terminal 3 so that the base station 2 and the terminal 3 When starting communication relay, the controller 4 operates as follows.

  The position information of the mobile relay device 1, the base station 2, and the terminal 3 is transmitted from the mobile relay device 1 to the controller 4 at a predetermined cycle. When the controller 4 receives the position information from the mobile relay device 1, the controller 4 executes the mobility control process (see FIG. 4) of the control unit 11 of the mobile relay device 1 according to the first embodiment, and The destination is determined, and an instruction to move to the determined destination is notified to the mobile relay device 1.

When the mobile relay device 1 receives a search signal from the terminal 3, the mobile relay device 1 notifies the controller 4 of reception of the search signal. When the controller 4 receives the search signal reception notification from the terminal 3, the controller 4 instructs the mobile relay device 1 to transmit a connection request to the base station 2. In response to the instruction from the controller 4, the mobile relay device 1 transmits a connection request to the base station 2 (FIG. 5, OP12).

  When receiving a response to the connection request from the base station 2 (FIG. 5, OP13: YES), the mobile relay device 1 notifies the controller 4 of reception of the response to the connection request. When the controller 4 receives a notification of reception of a response to the connection request from the mobile relay device 1, the controller 4 generates directivity control information of the high frequency antenna 109 of the mobile relay device 1 from the position information of the base station 2 and the terminal 3. Then, the mobile relay device 1 is notified.

  Upon receiving the directivity control information of the high frequency antenna 109 from the controller 4, the mobile relay device 1 controls the directivity of the high frequency antenna 109 according to the control information (OP14 in FIG. 5). When the directivity control of the high frequency antenna 109 is completed, the mobile relay device 1 notifies the controller 4 of the completion of the directivity control.

  When receiving notification of completion of directivity control from the mobile relay device 1, the controller 4 transmits an instruction to start wireless communication relay to the mobile relay device 1. When receiving the instruction from the controller 4, the mobile relay device 1 starts communication between the terminal 3 and the base station 2 (FIG. 5, OP15).

  For example, in the wireless communication system 100C, as in the second embodiment, the mobile relay device 1 moves to an area where the number of terminals 3 in the assigned area is the largest by detecting a search signal from the terminal 3, When starting relay of communication between the station 2 and the terminal 3, the controller 4 operates as follows.

  The position information of the mobile relay device 1, the base station 2, and the terminal 3 is transmitted from the mobile relay device 1 to the controller 4 at a predetermined cycle. When the mobile relay device 1 detects a search signal from the terminal 3 (FIG. 10, OP21: YES), the mobile relay device 1 notifies the controller 4 of detection of the search signal from the terminal 3. When the controller 4 is notified of the detection of the search signal from the terminal 3, it determines whether or not the terminal 3 is the terminal 3 in the area in charge of the mobile relay device 1 (OP22 in FIG. 10).

  When the search signal source terminal 3 is the terminal 3 in the area in charge of the mobile relay apparatus 1, the controller 4 detects the flight over the area in charge of the mobile relay apparatus 1 and the number of terminals in each area in charge. Instruct.

  When receiving an instruction from the controller 4, the mobile relay device 1 transmits a terminal detection signal in each assigned area, and detects the number of terminals 3 to which a response is returned (OP23 in FIG. 10). The mobile relay device 1 notifies the controller 4 of the number of terminals 3 to which the response of the terminal detection signal in each assigned area is returned.

  When receiving the notification of the number of terminals in each assigned area from the mobile relay apparatus 1, the controller 4 determines the area with the largest number of terminals as the area to which the mobile relay apparatus 1 is to be moved, and The mobile relay apparatus 1 is notified of the movement instruction. When receiving the notification from the controller 4, the mobile relay device 1 moves to the destination area (FIG. 10, OP24). When the movement to the movement destination area is completed, the mobile relay device 1 notifies the controller 4 of the completion of movement.

  Upon receiving notification of completion of movement from the mobile relay device 1, the controller 4 generates directivity control information for the high frequency antenna 109 of the mobile relay device 1 based on the information on the area in charge of the mobile relay device 1. Then, the mobile relay device 1 is notified.

  Upon receiving the directivity control information of the high frequency antenna 109 from the controller 4, the mobile relay device 1 controls the directivity of the high frequency antenna 109 according to the control information (OP26 in FIG. 10). When the directivity control of the high frequency antenna 109 is completed, the mobile relay device 1 notifies the controller 4 of the completion of the directivity control.

  Thereafter, for example, in the wireless communication system 100C, similarly to the case where the same control as in the first embodiment is performed, the controller 4 relays the wireless communication between the terminal 3 and the base station 2 by the mobile relay device 1. Processing is controlled.

  Therefore, in the wireless communication system 100C according to the third embodiment, the controller 4 performs the determination process performed by the mobile relay device 1 in place of the mobile relay device 1 in the first embodiment or the second embodiment.

  FIG. 13 is a diagram illustrating an example of a hardware configuration of the controller 4. The controller 4 is a dedicated computer, for example. The controller 4 includes a processor 401, a main storage device 402, an auxiliary storage device 403, and a network interface 404. These are connected to each other by a bus.

  The auxiliary storage device 403 stores the OS, various programs, and data used by the CPU 401 when executing each program. The auxiliary storage device 403 is, for example, a nonvolatile memory such as an EPROM (Erasable Programmable ROM), a flash memory, or a hard disk drive. The auxiliary storage device 403 stores, for example, a mobile relay control program. The mobile relay control program is a program for controlling the mobile relay device 1.

  The main storage device 402 is a storage device that provides the processor 401 with a storage area and a work area for loading a program stored in the auxiliary storage device 403, and is used as a buffer. The main storage device 402 includes, for example, a semiconductor memory such as a ROM (Read Only Memory) and a RAM.

  The processor 401 executes various processes by loading the OS and various application programs held in the auxiliary storage device 403 into the main storage device 402 and executing them. The number of processors 401 is not limited to one, and a plurality of processors 401 may be provided. The processor 401 is an example of a “control unit” of the “control device”.

  The network interface 404 is an interface for inputting / outputting information to / from the network. The network interface 404 is an interface corresponding to a wireless LAN, for example. Data transmitted from the mobile relay device 1 to the controller 4 is relayed to the base station 2 and received by the network interface 404. The network interface 404 is an example of a “transmitter” of the “control device”.

  Note that the hardware configuration of the controller 4 shown in FIG. 13 is an example, and is not limited to the above, and components can be omitted, replaced, or added as appropriate according to the embodiment. For example, the server 3 may include a portable recording medium driving device and execute a program recorded on the portable recording medium. The portable recording medium is, for example, an SD card, a miniSD card, a microSD card, a USB (Universal Serial Bus) flash memory, a CD (Compact Disc), a DVD (Digital Versatile Disc), a Blu-ray (registered trademark) Disc, or a flash. A recording medium such as a memory card.

FIG. 14 is a diagram illustrating an example of a functional configuration of the controller 4. The controller 4 includes a control unit 41, a network transmission / reception unit 42, a base station information DB 43, a terminal information DB 44, and a mobile relay device information DB 45 as functional components. These are functional components achieved by the processor 401 of the controller 4 executing the mobile relay control program in the auxiliary storage device 403.

  The network transmission / reception unit 42 is an interface with the network interface 404. The network transmission / reception unit 42 receives, for example, the location information of the mobile relay device 1, the base station 2, and the terminal 3 from the mobile relay device 1, the notification of detection of the search signal from the terminal 3, etc. via the base station 2. . The network transmission / reception unit 42 outputs the location information of the mobile relay device 1, the base station 2, and the terminal 3 from the mobile relay device 1, the notification of detection of the search signal from the terminal 3, and the like to the control unit 41.

  In addition, when receiving an input of a destination instruction to the mobile relay device 1 from the control unit 41, the network transmission / reception unit 42 transmits the destination instruction to the terminal 3 through the network interface 404.

  The control unit 41 receives from the mobile transmission / reception unit 42 location information of the mobile relay device 1, the base station 2, and the terminal 3, a notification of search signal detection from the terminal 3, and the like from the mobile relay device 1. The control unit 41 stores the position information of the mobile relay device 1 in the mobile relay device information DB 45. The control unit 41 stores the position information of the base station 2 in the base station information DB 43. The control unit 41 stores the position information of the terminal 3 in the terminal information DB 44.

  In the wireless communication system 100C, when the same service as that of the first embodiment is implemented, the control unit 41 receives the position information of the mobile relay device 1 and the terminal 3 and inputs the mobile relay device 1 and the terminal 3 It is determined whether or not the latitude and longitude included in the position information match. When the latitude and longitude included in the location information of the mobile relay device 1 and the terminal 3 do not match, the control unit 41 determines the latitude and longitude included in the location information of the terminal 3 as the destination of the mobile relay device 1, An instruction to move the mobile relay device 1 to the destination is output to the network transmission / reception unit 42.

  In the wireless communication system 100C, when the same service as that of the second embodiment is performed, the control unit 41 performs the following processing. When the notification of the detection of the search signal from the terminal 3 is input, the control unit 41 sends a flight instruction over the assigned area and an instruction for detecting the number of terminals in each assigned area to the mobile relay device 1 via network transmission / reception. To the unit 42. When the notification of the number of terminals in each assigned area is input from the mobile relay device 1, the control unit 41 determines the area with the largest number of terminals as the destination area, and moves to the destination area for the mobile relay device 1. Is output to the network transmitting / receiving unit 42.

  Further, the control unit 41 may be configured such that, for example, as described above, the mobile relay device 1 is shown in FIG. 5 when any service similar to that in the first or second embodiment is performed in the wireless communication system 100C. An instruction is transmitted to the mobile relay device 1 so as to operate in accordance with the relay control process.

  That is, in the first embodiment or the second embodiment, the control unit 41 performs, for example, the determination processing performed by the mobile relay device 1 in the processing illustrated in FIGS. 4, 5, and 10 on the mobile relay device 1. Do it on your behalf.

  The base station information DB 43, the terminal information DB 44, and the mobile relay device information DB 45 are each created in the storage area of the auxiliary storage device 403 of the controller 4. The base station information DB 43, the terminal information DB 44, and the mobile relay device information DB 45 store the position information of the base station 2, the terminal 3, and the mobile relay device 1, respectively.

  According to the third embodiment, a plurality of mobile relay devices 1 can be controlled in an integrated manner. In addition, setting changes such as a change of the assigned area of each mobile relay device 1 can be easily performed by transmitting from the controller 4 to the mobile relay device 1, and it is possible to flexibly cope with fluctuations in the null spot. Since the controller 4 performs the determination process, the performance of the processor 101 mounted on the mobile relay device 1 may be low, and the cost of the mobile relay device 1 itself can be suppressed.

<Processor>
The CPU is also called an MPU (Microprocessor) or processor. The CPU is not limited to a single processor, and may have a multiprocessor configuration. A single CPU connected by a single socket may have a multi-core configuration. At least a part of the processing of each unit may be performed by a processor other than the CPU, for example, a dedicated processor such as a digital signal processor (DSP), a graphics processing unit (GPU), a numerical operation processor, a vector processor, or an image processing processor. good. In addition, at least a part of the processing of each unit may be an integrated circuit (IC) or other digital circuit. In addition, an analog circuit may be included in at least a part of each of the above parts. Integrated circuits are LSI, Application Specific Integrated Circuit (ASIC), Programmable Logic Device (PLD)
including. The PLD includes, for example, a field-programmable gate array (FPGA). Each of the above units may be a combination of a processor and an integrated circuit. The combination is called, for example, a microcontroller (MCU), a SoC (System-on-a-chip), a system LSI, a chip set, or the like.

<Recording medium>
A program for causing a computer or other machine or device (hereinafter, a computer or the like) to realize any of the above functions can be recorded on a recording medium that can be read by the computer or the like. The function can be provided by causing a computer or the like to read and execute the program of the recording medium.

Here, a computer-readable recording medium is a non-temporary recording medium in which information such as data and programs is accumulated by electrical, magnetic, optical, mechanical, or chemical action and can be read from a computer or the like. A typical recording medium. Examples of such a recording medium that can be removed from a computer or the like include a flexible disk, a magneto-optical disk, a CD-ROM, a CD-R / W, a DVD, a Blu-ray disk, a DAT, an 8 mm tape, a flash memory, and the like. There are cards. In addition, as a recording medium fixed to a computer or the like, there are a hard disk, a ROM (read only memory), and the like. Further, an SSD (Solid State Drive) can be used as a recording medium removable from a computer or the like, or as a recording medium fixed to the computer or the like.

DESCRIPTION OF SYMBOLS 1 Mobile relay apparatus 2 Base station 3 Terminal 4 Controller 11 Control part 12 Position information receiving part 13 Position estimation part 14 Directivity control part 15A Low frequency receiving part 15B Low frequency transmitting part 16 Peripheral apparatus information database 17A High frequency receiving part 17B High Frequency transmission unit 18 Relay processing unit 101 Processor 102 RAM
103 Non-volatile memory 104A Motor 104B Propeller 105 Positioning unit 106 Low frequency radio communication unit 107 Low frequency antenna 108 High frequency radio communication unit 109 High frequency antenna

Claims (8)

A wireless communication unit that receives a control signal indicating that the terminal device is in a state where wireless communication with the communication destination device is not possible;
A propulsion device for moving to a position capable of wireless communication with the terminal device and the communication destination device;
When the control signal is received from the terminal device, processing related to relay of wireless communication between the terminal device and the communication destination device is performed at the position where the terminal device and the communication destination device can perform wireless communication. A control unit;
A mobile relay device comprising: The wireless communication unit receives position information of the terminal device,
The control unit determines a position where wireless communication with the terminal device and the communication destination device is possible based on position information of the terminal device.
The mobile relay device according to claim 1. The mobile relay device can fly by the propulsion device,
The control unit determines a position at a predetermined altitude at a position indicated by position information of the terminal device as a position where wireless communication with the terminal device and the communication destination device is possible.
The mobile relay device according to claim 2. When the control signal is received from the terminal device, the control unit detects the number of terminal devices capable of wireless communication with the own device in each of a plurality of areas, and satisfies a predetermined condition among the plurality of areas. Determining a predetermined position in the area as a position capable of wireless communication with the terminal device and the communication destination device;
The mobile relay device according to claim 2. A second wireless communication unit that relays wireless communication between the terminal device and the communication destination device in a second frequency band higher than the first frequency band used by the wireless communication unit;
An antenna that transmits and receives radio waves in the second frequency band,
The control unit controls the directivity of the antenna so that radio waves of the second frequency band can reach the plurality of areas after moving to the predetermined position in an area that satisfies the predetermined condition.
The mobile relay device according to claim 4. When the control signal is received from the terminal device, the control unit instructs the propulsion device to move to the predetermined position in each area for each of the plurality of areas, and the predetermined unit in the area In the position, a terminal detection signal is transmitted, the number of terminal devices that have received a response to the terminal detection signal is counted, and the number of terminal devices that can wirelessly communicate with the own device in each of the plurality of areas is detected.
The mobile relay device according to claim 4 or 5. A mobile relay device equipped with a propulsion device
The propulsion unit moves to a position where it can wirelessly communicate with the terminal device and the communication destination device,
When receiving a control signal indicating that wireless communication with the communication destination device is not possible from the terminal device, the terminal device and the communication destination at the position where wireless communication with the terminal device and the communication destination device is possible. Perform processing related to relay of wireless communication with the device,
Mobile relay method. A mobile relay device that relays wireless communication between the communication destination device and the terminal device;
A control device for controlling the mobile relay device;
A mobile relay system including:
The control device includes:
A control unit for determining a position where the mobile relay device can wirelessly communicate with the terminal device and the communication destination device;
A transmission unit that transmits to the mobile relay device a position where the mobile relay device can wirelessly communicate with the terminal device and the communication destination device;
With
The mobile relay device is
A wireless communication unit that receives from the control device a position where wireless communication is possible with the terminal device and the communication destination device, and a control signal indicating that wireless communication with the communication destination device is not possible from the terminal device;
A propulsion device for moving to a position capable of wireless communication with the received terminal device and the communication destination device;
A control unit that performs processing related to relay of wireless communication between the terminal device and the communication destination device when the control signal is received from the terminal device;
Comprising
Mobile relay system.

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